This invention relates to a safety razor system made up of a razor blade assembly which includes an expandable shaving insert made up of or including a water-soluble shaving aid and an overcap. More particularly, this invention relates to the razor blade assembly/overcap combination which not only protects the user and the blades of the razor assembly, but also substantially prevents the razor blade assembly from sticking to the overcap.
It is known in the art to provide a razor blade assembly, of the wet shave type, having a cartridge which includes shaving inserts which expands when wet. Such shaving inserts are well known in the art and disclosed, for example in U.S. Pat. No. 4,170,821 and published British Patent Application No. GB 2024082A, the disclosures of which are incorporated herein by reference.
It is also well known in the art that such shaving inserts may include water-soluble polymers or other water-leachable shaving aid materials such as polyethylene oxide in a mix with a water-soluble polymer such as polystyrene. The mix is molded into an insert and secured to a cartridge in a cavity in the cap of the razor blade assembly. As an alternative, the shaving insert or aid may be formed as an integral part of the cap structure of the razor blade assembly.
When such a shaving insert is exposed to water during the shaving process, the shaving insert expands with respect to the upper surface of the cap. Such expansion, especially when the shaving insert is wet, may result in the shaving insert sticking to objects with which it comes in contact. This problem is particularly acute when it is desirous to provide an overcap which not only protects the blade means of the associated razor blade assembly but also to protect and preserve the shaving insert itself.
It is also well known in the art that individual overcaps may cooperate with a disposable cartridge or cooperate with an entire disposable razor. Although applicable to either a cartridge or disposable razor, overcaps are most usually used in conjunction with disposable razor systems, since the cartridges are usually separately protected in a dispenser.
The overcap must also protect the razor blade assembly from damage during transportation and be capable of being repositioned on the cartridge between shaves to protect the user and the cartridge.